re_scan.py 文件源码

def __init__(self, rules, flags=0):
        pattern = Pattern()
        pattern.flags = flags
        if sys.version_info < (3, 0):
            pattern.groups = len(rules) + 1
        _og = pattern.opengroup
        pattern.opengroup = lambda n: _og(n and '%s\x00%s' % (name, n) or n)

        self.rules = []
        subpatterns = []
        for group, (name, regex) in enumerate(rules, 1):
            last_group = pattern.groups - 1
            subpatterns.append(
                SubPattern(pattern, [
                    (SUBPATTERN, (group, parse(regex, flags, pattern))),
                ]))
            self.rules.append((name, last_group, pattern.groups - 1))
        self._scanner = sre_compile(
            SubPattern(pattern, [(BRANCH, (None, subpatterns))])).scanner